Understanding
The process of determining the elevations of a series of points at measured intervals along a line.
What is profile leveling?
A permanent point of known or assumed elevation from which a leveling survey is started.
What is a benchmark?
What equipment is used for profile leveling?
A leveling instrument and a leveling rod
Why are field notes important?
They provide a record of measurements and ensure the accuracy of the survey
The maximum acceptable distance that a survey may be off in measurement after being closed out on the benchmark.
What is allowable error?
Subtracting the foresight from the height of the instrument
How is elevation calculated?
A level reading taken on a point of unknown elevation.
What is a foresight?
What is the procedure for a profile survey?
Take readings at designated stations and calculate elevations
What should be included in field notes?
Date, time, weather conditions, names of team members, and measurement readings.
What factors affect allowable error?
The number of rod readings and the distance each reading covers.
locating drains, roads, dams, and other earth structures
What is the purpose of profile leveling?
A level reading taken on a point of known or assumed elevation
What is a backsight?
Describe the steps in completing a survey.
Set up the equipment, take measurements, record field notes, and close the loop.
How should field notes be organized?
Use a table of contents, and number pages with clear headings for each entry.
Why might a survey need to be repeated?
If the error of the survey is greater than the allowable amount calculated
installing field tiles, constructing roads, and surveying land for various purposes.
What is the application of profile leveling?
The elevation of the level line of sight with respect to the benchmark.
What is the height of instrument?
What is the significance of closing the loop in surveying?
It ensures the accuracy of the survey by taking a final reading on the benchmark.
What is the format for entries in field notes?
Each entry should include columns for station, backsight, foresight, height of instrument, and elevation.
What is the final error of closure?
It is proportional to the square root of the number of rod readings and indicates the reliability of the survey results
What is the difference between slope and profile leveling?
Profile leveling takes measurements of a series of points along a slope, while slope calculations are determined from measurements between just two points.
The location of the leveling rod when a reading is taken.
What happens if the error exceeds allowable limits?
The survey should be repeated to ensure accuracy.
How should sketches be included in field notes?
Sketches should be to scale and include north orientation and relevant features.
How is allowable error calculated?
Divide the total length of the traverse by 100, find the square root of that number, and multiply by a factor (0.014 or 0.007).